Datacentre networking has recently been receiving an ever-increasing amount of attention, among other things due to the introduction of new approaches to creating telecom services, namely Dynamic Service Chaining, DSC, and the corresponding enabling technologies like Network Function Virtualisation, NFV. Specifically, virtualising network functions in the software and running them on generalised hardware platforms may bring additional degree of flexibility in service provisioning and control, where a network function can dynamically be provisioned, modified (e.g. up and down-scaling), migrated and terminated. This enables service providers to push most of the building blocks of the services into datacentres, where they can dynamically instantiate a specific set of functions, pipe them together and offer a new service in a short amount of time.
A major requirement of an NFV infrastructure (e.g. a datacentre) is the ability to dynamically steer the traffic between several virtualised network functions (VNFs)—running on potentially different servers—back and forth. This dynamicity puts additional constraints on the forwarding and control architectures of the datacentre networks. Specifically, in a datacentre utilised as an NFV infrastructure there is a need for flexible, fast and cost-efficient transport architecture both between datacentre in/output and the servers as well as among servers themselves. An additional requirement here, making the task even more challenging, is the large capacity requirement in particular for aggregate services. Meeting all these requirements is a quite challenging task in conventional datacentres, which typically contain thousands of hierarchically structured switches and routers.